Everyone wants perfect white teeth. While there are different tooth whitening systems available, focusing on the causes of tooth discolouration is important. Without paying attention to the cause of the tooth stains you have you won’t get the long-lasting results you expect from tooth whitening treatments. Here are four causes of tooth discolouration you might not expect.Fluoride treatments89% of Australians’ water supply is fluoridated, and this exposure to fluoride is important for reducing the risk of dental decay. Despite this, too much exposure to fluoride when teeth are growing can lead to white or even brown staining on the teeth. This is called fluorosis and is uncommon with levels of fluoride found in Australian drinking water. Excessive fluoride from using adult toothpaste, too much toothpaste, swallowing toothpaste or take extra fluoride treatments can cause it, so it’s important that children use toothpaste designed just for them and learn not to swallow it. Tooth whitening can help with some of these stains but it’s much better to avoid them in the first place.AgingOur teeth have two main parts: the protective white enamel which covers them and the boney layer beneath the enamel which is called dentin. As we get older enamel becomes thinner. This means the dentin’s yellow-brown colour shows through the enamel more easily. The dentin can also darken or become more intensely coloured as we age due to deeper coloured dentin being laid down on the inside of the tooth. This type of staining can be more difficult to manage with tooth whitening, but you can slow its onset by avoiding things that damage the enamel of your teeth such as acidic foods and drinks.MedicationMedications for allergies, high blood pressure and some mental health conditions can all cause tooth staining, however, the worst culprit is a type of antibiotic called tetracyclines. These usually only result in stains if your mother had them while she was pregnant. They are given with caution in pregnant women for this reason. If you have concerns about the impact medication may have on your teeth discuss this with your doctor and dentist, especially if you are going ahead with a tooth whitening treatment.AlcoholWhile many people know that red wine can cause tooth stains not many people know that any alcohol consumption can lead to tooth discolouration. Red wines and fruit wines can stain the enamel or surface of the teeth, but beer and dark coloured spirits can also stain enamel. Most alcoholic beverages are acidic, which leaves the enamel more vulnerable to staining. It also damages the enamel, making it thin more and potentially exposing the darker coloured dentin beneath. Drinking too much alcohol can also leave you with a dry mouth which will leave you at a higher risk of tooth decay. Tooth whitening will be able to manage stains to the enamel, but it’s important to rinse your mouth after drinking and only consume alcohol in moderation if you don’t want to undo the hard work done to whiten your teeth.